Recently, blood flow has been improved by widening a lesion (stenosed portion) of the coronary artery with a balloon catheter, in treatment of, for example, acute myocardial infarction and angina pectoris, percutaneous coronary intervention (percutaneous transluminal coronary angioplasty). For example, refer to Japanese Patent Application Publication No. 2008-501408. Treatment using a balloon catheter may also be performed to improve a lesion formed inside other blood vessels, the bile duct, the trachea, the esophagus, the urethra, and other body lumens.
Generally, a balloon catheter includes a long shaft and a balloon on the distal side of the shaft. The balloon inflates in the radial direction (i.e., expands radially outward by inflation). The balloon catheter is delivered to a stenosed portion in a body after a preceding guide wire is inserted through to the stenosed portion. When the balloon is positioned at the target stenosed site, the balloon is inflated by pressure-feeding an inflation fluid into the balloon. The stenosed portion can thus be widened.
In order to effectively treat a lesion area, the balloon of the balloon catheter is required to have sufficient strength to possess a desired balloon shape when being maximally inflated and to widen the lesion. Therefore, in order to apply high-pressure resistance, low compliance properties, and the like to a balloon, a configuration has been proposed in the related art in which a net-shaped reinforcement member is provided in a wall configuring the balloon. For example, refer to Japanese Patent Application Publication No. 2008-501408.